misc: pci_endpoint_test: Give disabled BARs a distinct error code

The current code returns -ENOMEM if test->bar[barno] is NULL.

There can be two reasons why test->bar[barno] is NULL:

  1) The pci_ioremap_bar() call in pci_endpoint_test_probe() failed.
  2) The BAR was skipped, because it is disabled by the endpoint.

Many PCI endpoint controller drivers will disable all BARs in their
init function. A disabled BAR will have a size of 0.

A PCI endpoint function driver will be able to enable any BAR that
is not marked as BAR_RESERVED (which means that the BAR should not
be touched by the EPF driver).

Thus, perform check if the size is 0, before checking if
test->bar[barno] is NULL, such that we can return different errors.

This will allow the selftests to return SKIP instead of FAIL for
disabled BARs.

Signed-off-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20250123120147.3603409-3-cassel@kernel.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>

diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
index 0fa5ddd1969b288d8c0de1a357c5bce82a94023f..705659f5f0e96399bd87428eccc3069058c0a072 100644 (file)
--- a/drivers/misc/pci_endpoint_test.c
+++ b/drivers/misc/pci_endpoint_test.c
@@ -292,11 +292,13 @@ static int pci_endpoint_test_bar(struct pci_endpoint_test *test,
        void *read_buf __free(kfree) = NULL;
        struct pci_dev *pdev = test->pdev;
 
+       bar_size = pci_resource_len(pdev, barno);
+       if (!bar_size)
+               return -ENODATA;
+
        if (!test->bar[barno])
                return -ENOMEM;
 
-       bar_size = pci_resource_len(pdev, barno);
-
        if (barno == test->test_reg_bar)
                bar_size = 0x4;